Substance use and substance use disorders (SUD), with their associated disability, comorbidity and mortality, constitute major public health problems. Combatting these problems requires cutting-edge public health research conducted by scientists of the highest caliber. The Substance Abuse Epidemiology Training Program (SAETP) at Columbia University Medical Center (CUMC) was established in 2012 to train talented young scientists to become the next generation of leaders in substance abuse epidemiology. Thus far, SAETP has been very successful, competitively attracting fellows who are productive and successful during and after their training. Completed SAETP and SAETP-affiliated fellows have attained prestigious research positions in academic medical center settings. We now propose a 5-year renewal cycle for SAETP. CUMC offers a rich array of research and training resources for SAETP, based in the Department of Epidemiology, Mailman School of Public Health, in collaboration with the Department of Psychiatry. SAETP has a cells-to-society perspective on substance abuse epidemiology, offering training at multiple levels of causation ranging from molecular to large-scale social forces. With its specialized training for substance abuse epidemiology careers, SAETP is unique at CUMC. Dr. Deborah Hasin, SAETP director, is an internationally recognized substance abuse epidemiologist with extensive successful mentoring experience. She will continue to direct SAETP in its next cycle. The disciplines of the 23 other internationally recognized SAETP faculty members include epidemiology, psychology, medicine, sociology, biostatistics, neuroscience and genetics, making for an interdisciplinary program. SAETP faculty have outstanding records in publishing, funding, and mentoring productive and successful trainees. At any given time in the renewal, SAETP will be training 4 pre-doctoral fellows (for training periods of 3-5 years each), and 4 post-doctoral fellows (for training periods of 2-3 years each). Fellows will be selected based on interest in and commitment to substance abuse epidemiology, experience, and prior accomplishments. Recruitment efforts to enroll under-represented minority trainees have been successful, with 25% of SAETP fellows from such groups to date; we will continue these recruitment efforts. SAETP will provide broad, intensive training in substance abuse epidemiology and related areas; depth in one or more areas of specialization; methodological and conceptual skills, including formulation of key research questions and testable hypotheses, and how to design and conduct high-quality substance abuse epidemiology studies. Fellows will receive mentoring and co-mentoring, and participate in many training components, e.g., a weekly substance abuse epidemiology faculty-fellow seminar; academic courses; field placements. Training will enable fellows to publish papers, hone their presentation skills in seminars and conferences, learn to write grant proposals; become knowledgeable about the responsible conduct of research, and enhance collaboration and leadership skills.